Crystal-Face Tailored Graphitic Carbon Nitride Films for High-Performance Photoelectrochemical Cells

Graphitic carbon nitride (g-CN) has been widely studied as a promising candidate for water splitting, owing to its metal-free nature, moderate band gap, and low cost. However, its photocurrent density is still very low for photoelectrochemical cell applications. In this work, a crystal face tailored g-CN photoelectrode has been fabricated by a facile thermal vapor deposition method. We use the melamine formaldehyde resin as a new precursor and have successfully fabricated g-CN films. The intensity ratio between two typical peaks (100) and (001) of g-CN is very different from that in the existing literature. The water splitting photocurrent density is as high as 228.2 μA cm^-2 , which is 126.8 times higher than pure g-CN (1.8 μA cm^-2 ) at 1.23 V vs. reversible hydrogen electrodes under one sun illumination without sacrificial reagents and co-catalysts. The electrode shows the best performance, compared with the previously reported g-CN photoelectrodes.